Cross-shift changes in pulmonary function and occupational exposure to particulate matter among e-waste workers in Ghana.

Introduction: Little is known on the association between cross-shift changes in pulmonary function and personal inhalation exposure to particulate matter (PM) among informal electronic-waste (e-waste) recovery workers who have substantial occupational exposure to airborne pollutants from burning e-waste. Methods: Using a cross-shift design, pre- and post-shift pulmonary function assessments and accompanying personal inhalation exposure to PM (sizes <1, <2.5 µm, and the coarse fraction, 2.5-10 µm in aerodynamic diameter) were measured among e-waste workers (n = 142) at the Agbogbloshie e-waste site and a comparison population (n = 65) in Accra, Ghana during 2017 and 2018. Linear mixed models estimated associations between percent changes in pulmonary function and personal PM. Results: Declines in forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) per hour were not significantly associated with increases in PM (all sizes) among either study population, despite breathing zone concentrations of PM (all sizes) that exceeded health-based guidelines in both populations. E-waste workers who worked "yesterday" did, however, have larger cross-shift declines in FVC [-2.4% (95%CI: -4.04%, -0.81%)] in comparison to those who did not work "yesterday," suggesting a possible role of cumulative exposure. Discussion: Overall, short-term respiratory-related health effects related to PM exposure among e-waste workers were not seen in this sample. Selection bias due to the "healthy worker" effect, short shift duration, and inability to capture a true "pre-shift" pulmonary function test among workers who live at the worksite may explain results and suggest the need to adapt cross-shift studies for informal settings.

Association between toxic and essential metals in blood and global DNA methylation among electronic waste workers in Agbogbloshie, Ghana.

Aberrant global DNA methylation status is a known biomarker for increased disease risk, especially cancer. There is little published data on the association between toxic and essential metal mixtures and global DNA methylation in electronic waste (e-waste) workers. We aimed to establish the association between toxic and essential metals in blood and the effect of their interactions on global DNA methylation among e-waste recyclers and a reference group in Ghana. We used ICP-MS to measure the level of five metals (Se, Zn, Mn, Cd, and Pb) in the blood of 100 e-waste workers and 51 controls. We quantified blood DNA methylation levels of LINE-1 as an indicator of global DNA methylation. Cd, Mn, and Se levels were significantly higher in the reference group than in e-waste workers. Only Pb was significantly higher in the e-waste workers compared to the controls. Our linear regression analysis results showed a significant inverse association between Zn and LINE-1 DNA methylation (ßZn = - 0.912; 95% CI, - 1.512, - 0.306; p = 0.003) which corresponds to a 0.009 decrease in %LINE-1 methylation (95% CI, - 0.015, - 0.003; p = 0.003) for a 1% increase in Zn concentration. Potential interactions between Cd and Zn on global DNA methylation were observed. In summary, co-exposure to toxic and essential metals is associated with global (LINE-1) DNA methylation.

Effects of Elevated Temperatures on the Growth and Development of Adult Anopheles gambiae (s.l.) (Diptera: Culicidae) Mosquitoes.

Higher temperatures expected in a future warmer climate could adversely affect the growth and development of mosquitoes. This study investigated the effects of elevated temperatures on longevity, gonotrophic cycle length, biting rate, fecundity, and body size of Anopheles gambiae (s.l.) (Diptera: Culicidae) mosquitoes. Anopheles gambiae (s.l.) eggs obtained from laboratory established colonies were reared under eight temperature regimes (25, 28, 30, 32, 34, 36, 38, and 40°C), and 80 ± 10% RH. All adults were allowed to feed on a 10% sugar solution soaked in cotton wool; however, some mosquitoes were provided blood meal using guinea pig. Longevity was estimated for both blood-fed and non-blood-fed mosquitoes and analyzed using the Kaplan-Meier survival analysis. One-way ANOVA was used to test the effect of temperature on gonotrophic cycle length, biting rate, and fecundity. Adult measurement data were log-transformed and analyzed using ordinary least square regression with robust standard errors. Increasing temperature significantly decreased the longevity of both blood-fed (Log-rank test; X2(4) = 904.15, P < 0.001) and non-blood-fed (Log-rank test; X2(4) = 1163.60, P < 0.001) mosquitoes. In addition, the fecundity of mosquitoes decreased significantly (ANOVA; F(2,57) = 3.46, P = 0.038) with an increase in temperature. Body size (ß = 0.14, 95% CI, 0.16, 0.12, P < 0.001) and proboscis length (ß = 0.13, 95% CI, 0.17, 0.09, P < 0.001) significantly decreased with increasing temperature from 25 to 34°C. Increased temperatures expected in a future warmer climate could cause some unexpected effects on mosquitoes by directly influencing population dynamics and malaria transmission.

Effects of elevated temperatures on the development of immature stages of Anopheles gambiae (s.l.) mosquitoes.

OBJECTIVE: This study investigated the effects of temperature on the development of the immature stages of Anopheles gambiae (s.l.) mosquitoes. METHODS: Mosquito eggs were obtained from laboratory established colonies and reared under eight temperature regimes (25, 28, 30, 32, 34, 36, 38 and 40°C), and 80 ± 10% relative humidity. Larvae were checked daily for development to the next stage and for mortality. Pupation success, number of adults produced and sex ratio of the newly emerged adults were recorded. Larval survival was monitored every 24 h, and data were analysed using Kaplan-Meier survival analysis. Analysis of variance was used where data followed normal distribution, and a Kruskal-Wallis test where data were not normally distributed. Larval and pupal measurements were log-transformed and analysed using ordinary least square regression with robust standard errors. RESULTS: Increasing the temperature from 25 to 36°C decreased the development time by 10.57 days. Larval survival (X2 (6) = 5353.12, p < 0.001) and the number of adults produced (X2 (5) = 28.16, p < 0.001) decreased with increasing temperature. Increasing temperatures also resulted in significantly smaller larvae and pupae (p < 0.001). At higher temperatures, disproportionately more male than female mosquitoes were produced. CONCLUSIONS: Increased temperature affected different developmental stages in the life cycle of An. gambiae (s.l.) mosquitoes, from larval to adult emergence. This study contributes to the knowledge on the relationship between temperature and Anopheles mosquitoes and provides useful information for modelling vector population dynamics in the light of climate change.

Association between global DNA methylation (LINE-1) and occupational particulate matter exposure among informal electronic-waste recyclers in Ghana.

This study examined the associations between PM (2.5 and 10) and global DNA methylation among 100 e-waste workers and 51 non-e-waste workers serving as controls. Long interspersed nucleotide repetitive elements-1 (LINE-1) was measured by pyrosequencing. Personal PM2.5 and PM10 were measured over a 4-hour work-shift using real-time particulate monitors incorporated into a backpack . Linear regression models were used to assess the association between PM and LINE-1 DNA methylation. The concentrations of PM2.5 and PM10 were significantly higher among the e-waste workers than the controls (77.32 vs 34.88, p < 0.001 and 210.21 vs 121.92, p < 0.001, respectively). PM2.5 exposure was associated with increased LINE-1 CpG2 DNA methylation (ß = 0.003; 95% CI; 0.001, 0.006; p = 0.022) but not with the average of all 4 CpG sites of LINE-1. In summary, high levels of PM2.5 exposure was associated with increased levels of global DNA methylation in a site-specific manner.

Personal exposure to particulate matter and heart rate variability among informal electronic waste workers at Agbogbloshie: a longitudinal study.

BACKGROUND: Informal electronic waste recycling activities are major contributors to ambient air pollution, yet studies assessing the effects or relationship between direct/continuous exposure of informal e-waste workers to particulate matter and cardiovascular function are rare. METHODS: Repeated measurements of fractions of PM2.5, PM10-2.5, and PM10 in personal air of informal e-waste workers, (n = 142) and a comparable group (n = 65) were taken over a period of 20 months (March 2017 to November, 2018). Concurrently, 5-min resting electrocardiogram was performed on each participant to assess resting heart rate variability indices. Linear mixed-effects models were used to assess the association between PM fractions and cardiac function. RESULTS: SDNN, RMSSD, LF, HF and LH/HF ratio were all associated with PM. Significant associations were observed for PM2.5 and Mean NN (p = 0.039), PM10 and SDNN (p = 0.035) and PM 10-2.5 and LH/HF (p = 0.039). A 10 µg/m3 increase in the concentrations of PM 2.5, PM10-2.5, and PM10 in personal air was associated with reduced HRV indices and increased resting HR. A 10 µg/m3 per interquartile (IQR) increase in PM10-2.5 and PM10, decreased SDNN by 11% [(95% CI: - 0.002- 0.000); (p = 0.187)] and 34% [(95% CI: - 0.002-0.001); (p = 0.035)] respectively. However, PM2.5 increased SDNN by 34% (95% CI: - 1.32-0.64); (p = 0.493). Also, 10 µg/m3 increase in PM2.5, PM10-2.5 and PM10 decreased RMSSD by 27% [(- 1.34-0.79); (p = 0.620)], 11% [(- 1.73, 0.95); (p = 0.846)] and 0.57% [(- 1.56-0.46); (p = 0.255%)]. CONCLUSION: Informal e-waste workers are at increased risk of developing cardiovascular disease from cardiac autonomic dysfunction as seen in reduced HRV and increased heart rate.

A Systematic Review of the Effects of Temperature on Anopheles Mosquito Development and Survival: Implications for Malaria Control in a Future Warmer Climate.

The rearing temperature of the immature stages can have a significant impact on the life-history traits and the ability of adult mosquitoes to transmit diseases. This review assessed published evidence of the effects of temperature on the immature stages, life-history traits, insecticide susceptibility, and expression of enzymes in the adult Anopheles mosquito. Original articles published through 31 March 2021 were systematically retrieved from Scopus, Google Scholar, Science Direct, PubMed, ProQuest, and Web of Science databases. After applying eligibility criteria, 29 studies were included. The review revealed that immature stages of An. arabiensis were more tolerant (in terms of survival) to a higher temperature than An. funestus and An. quadriannulatus. Higher temperatures resulted in smaller larval sizes and decreased hatching and pupation time. The development rate and survival of An. stephensi was significantly reduced at a higher temperature than a lower temperature. Increasing temperatures decreased the longevity, body size, length of the gonotrophic cycle, and fecundity of Anopheles mosquitoes. Higher rearing temperatures increased pyrethroid resistance in adults of the An. arabiensis SENN DDT strain, and increased pyrethroid tolerance in the An. arabiensis SENN strain. Increasing temperature also significantly increased Nitric Oxide Synthase (NOS) expression and decreased insecticide toxicity. Both extreme low and high temperatures affect Anopheles mosquito development and survival. Climate change could have diverse effects on Anopheles mosquitoes. The sensitivities of Anopeheles mosquitoes to temperature differ from species to species, even among the same complex. Notwithstanding, there seem to be limited studies on the effects of temperature on adult life-history traits of Anopheles mosquitoes, and more studies are needed to clarify this relationship.

Work-Related Exposures and Musculoskeletal Disorder Symptoms among Informal E-Waste Recyclers at Agbogbloshie, Ghana.

Recycling of electrical and electronic waste (e-waste) in developing countries is mostly conducted in the informal sector consisting of low skilled workers. Informal e-waste recycling predominantly involves the physically demanding work of manually collecting, dismantling and burning of e-waste items to extract reusable components and valuable metals including gold or copper. This cross-sectional study investigated the effects of manual e-waste recycling work on the musculoskeletal health of 176 workers at Agbogbloshie in Accra, Ghana - the largest informal e-waste dumpsites in Africa. Findings indicate significant associations between prolonged walking and weighted MSD symptom scores for the lower extremities, and between manual material handlings tasks and weighted MSD symptom scores for the upper extremities and lower back. The study calls attention to the need for ergonomics research in the informal work sector to promote safer practices and address a range of worker health concerns.

Global DNA (LINE-1) methylation is associated with lead exposure and certain job tasks performed by electronic waste workers.

OBJECTIVE: This study assessed the associations between blood and urine levels of toxic metals; cadmium (Cd) and lead (Pb), and methylation levels of the LINE-1 gene among e-waste and control populations in Ghana. METHODS: The study enrolled 100 male e-waste workers and 51 all-male non-e-waste workers or controls. The concentrations of Cd and Pb were measured in blood and urine using inductively coupled plasma mass spectrometry, while LINE1 methylation levels were assessed by pyrosequencing of bisulfite-converted DNA extracted from whole blood. Single and multiple metals linear regression models were used to determine the associations between metals and LINE1 DNA methylation. RESULTS: Blood lead (BPb) and urine lead (UPb) showed higher median concentrations among the e-waste workers than the controls (76.82 µg/L vs 40.25 µg/L, p ≤ 0.001; and 6.89 µg/L vs 3.43 µg/L, p ≤ 0.001, respectively), whereas blood cadmium (BCd) concentration was lower in the e-waste workers compared to the controls (0.59 µg/L vs 0.81 µg/L, respectively, p = 0.003). There was no significant difference in LINE1 methylation between the e-waste and controls (85.16 ± 1.32% vs 85.17 ± 1.11%, p = 0.950). In our single metal linear regression models, BPb was significantly inversely associated with LINE1 methylation in the control group (ßBPb = - 0.027, 95% CI - 0.045, - 0.010, p = 0.003). In addition, a weak association between BPb and LINE1 was observed in the multiple metals analysis in the e-waste worker group (ßBPb = - 0.005, 95% CI - 0.011, 0.000, p = 0.058). CONCLUSION: Continuous Pb exposure may interfere with LINE1 methylation, leading to epigenetic alterations, thus serving as an early epigenetic marker for future adverse health outcomes.

A PRELIMINARY ASSESSMENT OF PHYSICAL WORK EXPOSURES AMONG ELECTRONIC WASTE WORKERS AT AGBOGBLOSHIE, ACCRA GHANA.

Occupational exposure associated with unstructured, informal e-waste recycling has received very limited attention. This study aimed to quantify the occupational physical exposures among informal e-waste workers at the largest e-waste site in Africa. A cross-sectional field survey of 163 male e-waste workers was conducted using a self-report occupational physical activity questionnaire, along with direct work observations, and pedometer estimates of walking activity for a subset of workers (n = 42). Results indicated significant differences in self-reported 7-day work exposures among the three main e-waste job categories, namely, collectors (n = 70), dismantlers (n = 73) and burners (n = 20). Prolonged walking, sitting and standing on five or more days in the workweek was frequently reported by collectors (87%), dismantlers (82%) and burners (60%), respectively. Nearly 90% of collectors and burners and 60% of dismantlers reported lifting and carrying on five or more days in the workweek. The exposure combinations identified suggest a risk for musculoskeletal disorders (MSDs). Findings call attention to the need for research examining potential associations between physical exposures and MSDs affecting e-waste workers in Agbogbloshie. The high exposure variability both between and within workers has implications for future exposure assessments conducted in unregulated, informal work settings.

Musculoskeletal Disorder Symptoms among Workers at an Informal Electronic-Waste Recycling Site in Agbogbloshie, Ghana.

Informal recycling of electrical and electronic waste (e-waste) has myriad environmental and occupational health consequences, though information about the chronic musculoskeletal health effects on workers is limited. The aim of this study was to examine the prevalence and intensity of self-reported musculoskeletal disorder (MSD) symptoms among e-waste workers at Agbogbloshie in Ghana-the largest informal e-waste dumpsite in West Africa-relative to workers not engaged in e-waste recycling. A standardized musculoskeletal discomfort questionnaire was administered to 176 e-waste workers (73 collectors, 82 dismantlers, and 21 burners) and 41 workers in a reference group. The number of body parts with musculoskeletal discomfort were 1.62 and 1.39 times higher for collectors and dismantlers than burners, respectively. A 1-week discomfort prevalence was highest for collectors (91.8%) followed by dismantlers (89%), burners (81%), and the reference group (70.7%). The discomfort prevalence for e-waste workers was highest in the lower back (65.9%), shoulders (37.5%), and knees (37.5%). Whole-body pain scores (mean ± SE) were higher for collectors (83.7 ± 10.6) than dismantlers (45.5 ± 7.6), burners (34.0 ± 9.1), and the reference group (26.4 ± 5.9). Differences in prevalence, location, and intensity of MSD symptoms by the e-waste job category suggest specific work-related morbidity. Symptom prevalence and intensity call attention to the high risk for MSDs and work disability among informal e-waste workers, particularly collectors and dismantlers.

Opportunities and challenges in reducing personal inhalation exposure to air pollution among electronic waste recovery workers in Ghana.

BACKGROUND: Informal sector electronic waste (e-waste) recovery produces toxic emissions resulting from burning e-waste to recover valuable metals. OBJECTIVES: To identify high-risk worker groups by measuring relative levels of personal inhalation exposure to particulate matter (PM) of fine (≤2.5 µm) and coarse (2.5-10 µm) fractions (PM2.5 and PM2.5-10, respectively) across work activities among e-waste workers, and to assess how wind conditions modify levels of PM by activity and site location. METHODS: At the Agbogbloshie e-waste site, 170 partial-shift PM samples and time-activity data were collected from participants (N = 105) enrolled in the GeoHealth cohort study. Personal sampling included continuous measures of size-specific PM from the worker's breathing zone and time-activity derived from wearable cameras. Linear mixed models were used to estimate changes in personal PM2.5 and PM2.5-10 associated with activities and evaluate effect modification by wind conditions. RESULTS: Mean (±standard deviation) personal PM2.5 and PM2.5-10 concentrations were 80 (± 81) and 123 (± 139) µg m-3 , respectively. The adjusted mean PM2.5 concentration for burning e-waste was 88 µg m-3 , a 28% increase above concentrations during non-recovery activities (such as eating). Transportation-related and burning activities were associated with the highest PM2.5-10 concentrations. Frequent changes in wind direction were associated with higher PM2.5 concentrations when burning, and high wind speeds with higher PM2.5-10 concentrations when dismantling e-waste downwind of the burning zone.

Comparison of ergonomic risk factors and work-related musculoskeletal disorders among dismantler and burners of electronic waste in Agbogbloshie, Accra Ghana.

Rudimentary methods for electronic waste (e-waste) recycling employed in developing countries are a source of work-related musculoskeletal disorders (WRMSDs). A summarized comparison of WRMSDs and preliminary exposure assessment among e-waste dismantlers (D) and burners (B) in Agbogbloshie, Ghana is presented. A cross-sectional study was conducted to investigate WRMSDs and associated risk factors using the Cornell Musculoskeletal Discomfort Questionnaire and a newly developed ergonomic assessment tool. Results indicated higher WRMSDs prevalence in the lower back (68% D vs. 52% B; p = 0.172), shoulder (41% D vs. 29% B; p = 0.279) and upper arm (33% D vs 5% B; p = 0.010). Moderate to severe trunk flexion, high force exertion, repetition and vibration were prevalent risk factors among workers and were significantly higher in dismantlers than burners (p ≤ 0.001). Detailed ergonomic studies investigating the relationship between physical exposures and WRMSDs are needed to provide a deeper understanding of WRMSD causation in e-waste workers and more particularly in unstructured, unregulated work.

Micronutrient Status of Electronic Waste Recyclers at Agbogbloshie, Ghana.

Growing evidence suggests that micronutrient status is adversely impacted by toxic metals (e.g., cadmium, lead, and arsenic) exposures; however, the micronutrient status of e-waste recyclers who are amongst the highest metal-exposed groups is not known. This study, therefore, assessed the micronutrient status of e-waste recyclers using dietary information (2-day 24-h recall survey) and biomarker data (whole blood and urine) among 151 participants (100 e-waste recyclers at Agbogbloshie and 51 controls at Madina Zongo from the Accra region, Ghana) in March 2017. Biomarker levels of iron (Fe), calcium (Ca), magnesium (Mg), selenium (Se), zinc (Zn) and copper (Cu) were analyzed by the ICP-MS. Linear regression models were used to assess associations ofwork-related factors and sociodemographic characteristics with micronutrient intake, blood, and urine micronutrient levels. The results showed that apart from Fe and Zn, e-waste recyclers at Agbogbloshie did not meet the day-to-day dietary requirements for Ca, Cu, Se, and Mg intake. Except for the low levels of Mg and Fe detected in blood of e-waste recyclers, all other micronutrients measured in both blood and urine of both groups fell within their reference range. Exposure to biomass burning was associated with lower blood levels of Fe, Mg, and Zn among the e-waste recyclers. Further, among e-waste recyclers, significant relationships were found between the number of years spent recycling e-waste and urinary Ca and Cu excretion. Given that, some dietary and blood levels of micronutrients were below their reference ranges, the implementation of evidence-based nutrition strategies remains necessary among e-waste recyclers to reduce their risk of becoming malnourished.

Effect of Particulate Matter Exposure on Respiratory Health of e-Waste Workers at Agbogbloshie, Accra, Ghana.

Background: Direct and continuous exposure to particulate matter (PM), especially in occupational settings is known to impact negatively on respiratory health and lung function. Objective: To determine the association between concentrations of PM (2.5, 2.5-10 and 10 µm) in breathing zone and lung function of informal e-waste workers at Agbogbloshie. Methods: To evaluate lung function responses to PM (2.5, 2.5-10 and 10 µm), we conducted a longitudinal cohort study with three repeated measures among 207 participants comprising 142 healthy e-waste workers from Agbogbloshie scrapyard and 65 control participants from Madina-Zongo in Accra, Ghana from 2017-2018. Lung function parameters (FVC, FEV1, FEV1/FVC, PEF, and FEF 25-75) and PM (2.5, 2.5-10 and 10 µm) concentrations were measured, corresponding to prevailing seasonal variations. Socio-demographic data, respiratory exposures and lifestyle habits were determined using questionnaires. Random effects models were then used to examine the effects of PM (2.5, 2.5-10 and 10 µm) on lung function. Results: The median concentrations of PM (2.5, 2.5-10 and 10 µm) were all consistently above the WHO ambient air standards across the study waves. Small effect estimates per IQR of PM (2.5, 2.5-10 and 10 µm) on lung function parameters were observed even after adjustment for potential confounders. However, a 10 µg increase in PM (2.5, 2.5-10 and 10 µm) was associated with decreases in PEF and FEF 25-75 by 13.3% % [ß = -3.133; 95% CI: -0.243, -0.022) and 26.6% [ß = -0.266; 95% CI: -0.437, 0.094]. E-waste burning and a history of asthma significantly predicted a decrease in PEF by 14.2% [ß = -0.142; 95% CI: -0.278, -0.008) and FEV1 by 35.8% [ß = -0.358; 95% CI: -0.590, 0.125] among e-waste burners. Conclusions: Direct exposure of e-waste workers to PM predisposes to decline in lung function and risk for small airway diseases such as asthma and COPD.

Development of an observation-based tool for ergonomic exposure assessment in informal electronic waste recycling and other unregulated non-repetitive work.

Most existing ergonomic assessment tools are intended for routine work. Time- and cost-efficient observational tools for ergonomic assessment of unregulated work are lacking. This paper presents the development of an observation-based tool designed to investigate ergonomic exposures among informal electronic waste workers that could be applied to other unregulated jobs/tasks. Real time coding of observation is used to estimate the relative duration, intensity, and frequency of exposure to key work postures, forceful exertions, movements, contact stress and vibration. Time spent in manual material handling activities such as carrying, lifting and pushing/pulling of working carts are also estimated. A preliminary study conducted with 6 e-waste workers showed that the tool can easily be used with minimal training and good inter-observer agreement (i.e., 89% to 100%) for most risk factors assessed. This new assessment tool provides effective and flexible options for quantifying ergonomic exposures among workers engaged in unregulated, highly variable work.

Effect modifiers of lung function and daily air pollutant variability in a panel of schoolchildren.

BACKGROUND: Acute pollutant-related lung function changes among children varies across pollutants and lag periods. We examined whether short-term air pollutant fluctuations were related to daily lung function among a panel of children and whether these effects are modified by airway hyperresponsiveness, location and asthma severity. METHODS: Students from randomly selected grade 4 classrooms at seven primary schools in Durban, participated, together with asthmatic children from grades 3-6 (n=423). The schools were from high pollutant exposed communities (south) and compared with schools from communities with lower levels of pollution (north), with similar socioeconomic profiles. Interviews, spirometry and methacholine challenge testing were conducted. Bihourly lung function measurements were performed over a 3-week period in four phases. During all schooldays, students blew into their personal digital monitors every 1.5-2 hours. Nitrogen dioxide (NO2), nitrogen oxide (NO), sulphur dioxide and particulate matter (<10 µm diameter) (PM10) were measured at each school. Generalised estimating equations assessed lag effects, using single-pollutant (single or distributed lags) models. RESULTS: FEV1 declines ranged from 13 to 18 mL per unit increase in IQR for NO and 14-23 mL for NO2. Among the 5-day average models, a 20 mL and 30 mL greater drop in FEV1 per IQR for NO2 and NO, respectively, among those with airway hyperresponsiveness compared with those without. Effects were seen among those with normal airways. CONCLUSIONS: This first panel study in sub-Saharan Africa, showed significant declines in lung function, in response to NO and NO2 with effects modified by airway hyperresponsiveness or persistent asthma.

Derivation of Time-Activity Data Using Wearable Cameras and Measures of Personal Inhalation Exposure among Workers at an Informal Electronic-Waste Recovery Site in Ghana.

OBJECTIVES: Approximately 2 billion workers globally are employed in informal settings, which are characterized by substantial risk from hazardous exposures and varying job tasks and schedules. Existing methods for identifying occupational hazards must be adapted for unregulated and challenging work environments. We designed and applied a method for objectively deriving time-activity patterns from wearable camera data and matched images with continuous measurements of personal inhalation exposure to size-specific particulate matter (PM) among workers at an informal electronic-waste (e-waste) recovery site. METHODS: One hundred and forty-two workers at the Agbogbloshie e-waste site in Accra, Ghana, wore sampling backpacks equipped with wearable cameras and real-time particle monitors during a total of 171 shifts. Self-reported recall of time-activity (30-min resolution) was collected during the end of shift interviews. Images (N = 35,588) and simultaneously measured PM2.5 were collected each minute and processed to identify activities established through worker interviews, observation, and existing literature. Descriptive statistics were generated for activity types, frequencies, and associated PM2.5 exposures. A kappa statistic measured agreement between self-reported and image-based time-activity data. RESULTS: Based on image-based time-activity patterns, workers primarily dismantled, sorted/loaded, burned, and transported e-waste materials for metal recovery with high variability in activity duration. Image-based and self-reported time-activity data had poor agreement (kappa = 0.17). Most measured exposures (90%) exceeded the World Health Organization (WHO) 24-h ambient PM2.5 target of 25 µg m-3. The average on-site PM2.5 was 81 µg m-3 (SD: 94). PM2.5 levels were highest during burning, sorting/loading and dismantling (203, 89, 83 µg m-3, respectively). PM2.5 exposure during long periods of non-work-related activities also exceeded the WHO standard in 88% of measured data. CONCLUSIONS: In complex, informal work environments, wearable cameras can improve occupational exposure assessments and, in conjunction with monitoring equipment, identify activities associated with high exposures to workplace hazards by providing high-resolution time-activity data.

Processes and Challenges associated with informal electronic waste recycling at Agbogbloshie, a suburb of Accra, Ghana.

Electronic waste (e-waste) is a worldwide problem with regards to its increasing rate in the global waste stream. Its recycling is known to be associated with adverse health outcomes. The recycling site at Agbogbloshie is a major e-waste recycling hub which presents enormous health threats to the residents in this community as a result of exposure to complex mixtures of chemicals associated with the poor work methods employed. This paper describes the processes involved in e-waste recycling at Agbogbloshie and discusses some of the associated health and psychosocial challenges. Direct field observations and in-depth interviews of eight e-waste workers were conducted from November, 2017 to December, 2017. Results from a thematic analysis of obtained data suggest that inappropriate recycling methods, financial constraints, and the high physical demands of e-waste recycling work were associated with adverse musculoskeletal health conditions among the workers. A more systematic ergonomic study is currently being undertaken to quantify the associations between physical work exposures and worker musculoskeletal health among e-waste workers in Agbogbloshie. Further studies are needed that focus on locally adapted ergonomic interventions for effective recycling of e-waste and reducing the health risk to workers.

Impact of community respiratory viral infections in urban children with asthma.

BACKGROUND: Upper respiratory tract viral infections cause asthma exacerbations in children. However, the impact of natural colds on children with asthma in the community, particularly in the high-risk urban environment, is less well defined. OBJECTIVE: We hypothesized that children with high-symptom upper respiratory viral infections have reduced airway function and greater respiratory tract inflammation than children with virus-positive low-symptom illnesses or virus-negative upper respiratory tract symptoms. METHODS: We studied 53 children with asthma from Detroit, Michigan, during scheduled surveillance periods and self-reported respiratory illnesses for 1 year. Symptom score, spirometry, fraction of exhaled nitric oxide (FeNO), and nasal aspirate biomarkers, and viral nucleic acid and rhinovirus (RV) copy number were assessed. RESULTS: Of 658 aspirates collected, 22.9% of surveillance samples and 33.7% of respiratory illnesses were virus-positive. Compared with the virus-negative asymptomatic condition, children with severe colds (symptom score ≥5) showed reduced forced expiratory flow at 25% to 75% of the pulmonary volume (FEF25%-75%), higher nasal messenger RNA expression of C-X-C motif chemokine ligand (CXCL)-10 and melanoma differentiation-associated protein 5, and higher protein abundance of CXCL8, CXCL10 and C-C motif chemokine ligands (CCL)-2, CCL4, CCL20, and CCL24. Children with mild (symptom score, 1-4) and asymptomatic infections showed normal airway function and fewer biomarker elevations. Virus-negative cold-like illnesses demonstrated increased FeNO, minimal biomarker elevation, and normal airflow. The RV copy number was associated with nasal chemokine levels but not symptom score. CONCLUSION: Urban children with asthma with high-symptom respiratory viral infections have reduced FEF25%-75% and more elevations of nasal biomarkers than children with mild or symptomatic infections, or virus-negative illnesses.